rescue_has_many_nested_attributes.rb

class ReviewConfiguration < BaseRecord
  has_many :review_answers, dependent: :destroy
  accepts_nested_attributes_for :review_answers, allow_destroy: true
end

def review_answers_attributes=(attributes)
  attributes = attributes.map(&:deep_symbolize_keys)
  review_answer_ids = attributes.map{|el| el[:id]}.compact
  begin
    review_answers << ReviewAnswer.where(id: review_answer_ids)
    super attributes
  rescue ActiveRecord::RecordNotFound
    false
  end
end

# in controller
def update
  review = begin
            @review_configuration.update(review_configuration_params)
  rescue ActiveRecord::RecordNotFound
    record = params["review_configuration"]["review_answers_attributes"].map{|el| el["id"]}
    render json: {msg: "alguno de estos registros: #{record} no existen"} and return
  end
  if review
    render status: :ok, json: render_review_configuration(@review_configuration)
  else
    render status: :unprocessable_entity, json: { msg: @review_configuration.errors }
  end
 end